1. Field of the Invention
The present invention generally relates to an electrical connector, and particularly to an electrical connector for soldering with a printed circuit board.
2. Description of Prior Arts
It is well known that for an electrical connector mounted on a printed circuit board, wicking is always a serious problem. The gold plating contacting area of a contact is easily contaminated because the melted, poor-conductivity solder and flux may move along the surface of the contact and reach to the contacting area such that decrease electrical performance of the contact. Especially, due to continuing trends toward miniaturization and high density arrangement for making a connector, the contacts of connectors become smaller and smaller and make the wicking problem much more serious than before, so as to the electrical performance of the contact.
Some connectors are known which appear to have desirable anti-wicking characteristics by providing a cavity, or intervening space, between the contact area and solder tail portion of the contact, such as those described in Japanese Utility Model Publication No. 6-54273 and U.S. Pat. No. 5,735,696. Obviously, this kind of contact is too complicated for manufacturing so that unavoidably increases the manufacture-cost thereof.
The contact having another type of anti-wicking means is disclosed in U.S. Pat. No. 5,209,681. It recites an electrical contact has a tab provided in a passage which extends through the contact. The tab is dimensioned to provide a barrier, past which solder cannot flow. Consequently, as the contact is mounted to a printed circuit board, the tab prevents the solder from wicking from the mounting portion to the mating portion. However, such kind of contact is also too complicated for manufacturing so that unavoidably increases the manufacture-cost thereof, also.
Hence, it is desirable and more cost effective to have an electrical contact that can provide improved anti-wicking means to maintain the reliable electrical performance thereof when soldered to a printed circuit board.
Accordingly, it is an object of the present invention to provide an electrical connector having contacts which substantially eliminate wicking of molten solder or solder flux up from solder tail portions to contact portions when soldering the solder tail portions of the connector to a printed circuit board.
In order to achieve the above-mentioned object, an electrical connector for soldering with a printed circuit board in accordance with the present invention, includes an insulating housing defining a number of contact receiving channels therethrough, a number of contacts and a number of secondary conductors respectively received in corresponding contact receiving channels. Each contact includes a contact portion for electrically engaging with a complementary component, a tail portion for soldering to the printed circuit board, and an intermediate portion interconnecting the contact portion and the tail portion. Each intermediate portion is pre-coated with a Snxe2x80x94Pb plating which has a higher melting point than that of the soldering paste. The secondary conductors are respectively soldered with intermediate portions of corresponding contacts and a wicking barrier is formed on soldering area by heating the pre-coated Snxe2x80x94Pb plating. The wicking barriers block the melted soldering paste from passing therethrough to thereby protect contact portions when soldering the contacts to the printed circuit board.
Other objects, advantages and novel features of the invention will become more apparent from the following detailed description of the present embodiment when taken in conjunction with the accompanying drawings.